Oxe FM Synth is a freeware software synthesizer for Windows, in
two versions: VST Plug-in, and as standalone application.The sound bank
that come with the package include 48 programs (thanks to Teksonik and
Summa). To make new soundbanks, you can copy and rename the original
.bin file.

Rock
our free distortion synth , is out. You can do nicely nasty basses and
leads, distorted pads and sequence and some just basically weird sounds
with it.Rock comes with 2 skins , 128 presets, hundreds of waves , a
manual and is free.

Subconscious is a dual
arpeggiation sequence synth with oscillator crossfading, feedback
modulation, and independent filter and amp envelopes for both oscillator
sections. Subconscious has two different onboard sequencers, a gate
sequencer and a modulation sequencer, which can be used for stepped
sequences, gated pads and modulation of the pitch and filters.

Vember
Audio Shortcircuit
now freeware. Shortcircuit
was created as a reaction against the ongoing trend where software
samplers are being designed with the primary intent of library playback.
It is intended for people who, like us, consider a sampler to be a
musical instrument in its own right, and not just a way to emulate other
instruments.

Version 1.1.1 of Shortcircuit has some great features, including:

A streamlined GUI for fast editing at the
sample-zone level, in context sample preview and extensive drag &
drop support